With the development of wired and wireless communication technologies in terms of bandwidth and delay, especially with the deployment of the Long Term Evolution (LTE) systems, it is now possible to provide an application in a form of a video stream to a client device on a user's demand and to respond to the user's operations in real time. This is referred to as Application on Demand (AoD) service. The AoD service has a number of advantages. For example, applications are installed and executed on an AoD server instead of on a user device, such as an IPTV receiver, a mobile phone, a tablet computer or the like, whose processing capability and storage capacity are typically limited. In addition, it is much easier to update applications and protect their copyrights on the AoD server than on the user device. Here examples of the applications include office applications, enterprise vertical applications, games, etc.
As in traditional TV broadcast services, service providers typically desire to insert advertisements into AoD services. Picture in Picture (PiP) is a well known feature in the traditional TV broadcast services for presenting an advertisement to a user during TV program broadcasting. The PiP technique requires separate video processing devices for the advertisement and the TV program. Further, the video streams of the advertisement and the TV program are transmitted in separate channels and then combined at TV receivers. Hence, the PiP technique requires dedicated video processing devices and dedicated transmission channel for the advertisement.
WO 2011/075876 discloses a method for implementing PiP in an Internet Protocol (IP)-based mobile TV system. In the method, two separate channels (streaming sessions) are set up for streaming separate contents to a receiver, which then renders both contents on a screen at the same time. It can be seen that this PiP solution also requires separate channels for transmission of separate contents to be combined at the receiver.
There is thus a need for an improved solution for inserting an advertisement into a video stream of an AoD service.